drivers/media/video/ovcamchip/ovcamchip_core.c

   1 /* Shared Code for OmniVision Camera Chip Drivers
   2  *
   3  * Copyright (c) 2004 Mark McClelland <mark@alpha.dyndns.org>
   4  * http://alpha.dyndns.org/ov511/
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version. NO WARRANTY OF ANY KIND is expressed or implied.
  10  */
  11
  12 #define DEBUG
  13
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/delay.h>
  18 #include "ovcamchip_priv.h"
  19
  20 #define DRIVER_VERSION "v2.27 for Linux 2.6"
  21 #define DRIVER_AUTHOR "Mark McClelland <mark@alpha.dyndns.org>"
  22 #define DRIVER_DESC "OV camera chip I2C driver"
  23
  24 #define PINFO(fmt, args...) printk(KERN_INFO "ovcamchip: " fmt "\n" , ## args);
  25 #define PERROR(fmt, args...) printk(KERN_ERR "ovcamchip: " fmt "\n" , ## args);
  26
  27 #ifdef DEBUG
  28 int ovcamchip_debug = 0;
  29 static int debug;
  30 module_param(debug, int, 0);
  31 MODULE_PARM_DESC(debug,
  32   "Debug level: 0=none, 1=inits, 2=warning, 3=config, 4=functions, 5=all");
  33 #endif
  34
  35 /* By default, let bridge driver tell us if chip is monochrome. mono=0
  36  * will ignore that and always treat chips as color. mono=1 will force
  37  * monochrome mode for all chips. */
  38 static int mono = -1;
  39 module_param(mono, int, 0);
  40 MODULE_PARM_DESC(mono,
  41   "1=chips are monochrome (OVx1xx), 0=force color, -1=autodetect (default)");
  42
  43 MODULE_AUTHOR(DRIVER_AUTHOR);
  44 MODULE_DESCRIPTION(DRIVER_DESC);
  45 MODULE_LICENSE("GPL");
  46
  47 /* Registers common to all chips, that are needed for detection */
  48 #define GENERIC_REG_ID_HIGH       0x1C  /* manufacturer ID MSB */
  49 #define GENERIC_REG_ID_LOW        0x1D  /* manufacturer ID LSB */
  50 #define GENERIC_REG_COM_I         0x29  /* misc ID bits */
  51
  52 extern struct ovcamchip_ops ov6x20_ops;
  53 extern struct ovcamchip_ops ov6x30_ops;
  54 extern struct ovcamchip_ops ov7x10_ops;
  55 extern struct ovcamchip_ops ov7x20_ops;
  56 extern struct ovcamchip_ops ov76be_ops;
  57
  58 static char *chip_names[NUM_CC_TYPES] = {
  59         [CC_UNKNOWN]    = "Unknown chip",
  60         [CC_OV76BE]     = "OV76BE",
  61         [CC_OV7610]     = "OV7610",
  62         [CC_OV7620]     = "OV7620",
  63         [CC_OV7620AE]   = "OV7620AE",
  64         [CC_OV6620]     = "OV6620",
  65         [CC_OV6630]     = "OV6630",
  66         [CC_OV6630AE]   = "OV6630AE",
  67         [CC_OV6630AF]   = "OV6630AF",
  68 };
  69
  70 /* Forward declarations */
  71 static struct i2c_driver driver;
  72 static struct i2c_client client_template;
  73
  74 /* ----------------------------------------------------------------------- */
  75
  76 int ov_write_regvals(struct i2c_client *c, struct ovcamchip_regvals *rvals)
  77 {
  78         int rc;
  79
  80         while (rvals->reg != 0xff) {
  81                 rc = ov_write(c, rvals->reg, rvals->val);
  82                 if (rc < 0)
  83                         return rc;
  84                 rvals++;
  85         }
  86
  87         return 0;
  88 }
  89
  90 /* Writes bits at positions specified by mask to an I2C reg. Bits that are in
  91  * the same position as 1's in "mask" are cleared and set to "value". Bits
  92  * that are in the same position as 0's in "mask" are preserved, regardless
  93  * of their respective state in "value".
  94  */
  95 int ov_write_mask(struct i2c_client *c,
  96                   unsigned char reg,
  97                   unsigned char value,
  98                   unsigned char mask)
  99 {
 100         int rc;
 101         unsigned char oldval, newval;
 102
 103         if (mask == 0xff) {
 104                 newval = value;
 105         } else {
 106                 rc = ov_read(c, reg, &oldval);
 107                 if (rc < 0)
 108                         return rc;
 109
 110                 oldval &= (~mask);              /* Clear the masked bits */
 111                 value &= mask;                  /* Enforce mask on value */
 112                 newval = oldval | value;        /* Set the desired bits */
 113         }
 114
 115         return ov_write(c, reg, newval);
 116 }
 117
 118 /* ----------------------------------------------------------------------- */
 119
 120 /* Reset the chip and ensure that I2C is synchronized. Returns <0 if failure.
 121  */
 122 static int init_camchip(struct i2c_client *c)
 123 {
 124         int i, success;
 125         unsigned char high, low;
 126
 127         /* Reset the chip */
 128         ov_write(c, 0x12, 0x80);
 129
 130         /* Wait for it to initialize */
 131         msleep(150);
 132
 133         for (i = 0, success = 0; i < I2C_DETECT_RETRIES && !success; i++) {
 134                 if (ov_read(c, GENERIC_REG_ID_HIGH, &high) >= 0) {
 135                         if (ov_read(c, GENERIC_REG_ID_LOW, &low) >= 0) {
 136                                 if (high == 0x7F && low == 0xA2) {
 137                                         success = 1;
 138                                         continue;
 139                                 }
 140                         }
 141                 }
 142
 143                 /* Reset the chip */
 144                 ov_write(c, 0x12, 0x80);
 145
 146                 /* Wait for it to initialize */
 147                 msleep(150);
 148
 149                 /* Dummy read to sync I2C */
 150                 ov_read(c, 0x00, &low);
 151         }
 152
 153         if (!success)
 154                 return -EIO;
 155
 156         PDEBUG(1, "I2C synced in %d attempt(s)", i);
 157
 158         return 0;
 159 }
 160
 161 /* This detects the OV7610, OV7620, or OV76BE chip. */
 162 static int ov7xx0_detect(struct i2c_client *c)
 163 {
 164         struct ovcamchip *ov = i2c_get_clientdata(c);
 165         int rc;
 166         unsigned char val;
 167
 168         PDEBUG(4, "");
 169
 170         /* Detect chip (sub)type */
 171         rc = ov_read(c, GENERIC_REG_COM_I, &val);
 172         if (rc < 0) {
 173                 PERROR("Error detecting ov7xx0 type");
 174                 return rc;
 175         }
 176
 177         if ((val & 3) == 3) {
 178                 PINFO("Camera chip is an OV7610");
 179                 ov->subtype = CC_OV7610;
 180         } else if ((val & 3) == 1) {
 181                 rc = ov_read(c, 0x15, &val);
 182                 if (rc < 0) {
 183                         PERROR("Error detecting ov7xx0 type");
 184                         return rc;
 185                 }
 186
 187                 if (val & 1) {
 188                         PINFO("Camera chip is an OV7620AE");
 189                         /* OV7620 is a close enough match for now. There are
 190                          * some definite differences though, so this should be
 191                          * fixed */
 192                         ov->subtype = CC_OV7620;
 193                 } else {
 194                         PINFO("Camera chip is an OV76BE");
 195                         ov->subtype = CC_OV76BE;
 196                 }
 197         } else if ((val & 3) == 0) {
 198                 PINFO("Camera chip is an OV7620");
 199                 ov->subtype = CC_OV7620;
 200         } else {
 201                 PERROR("Unknown camera chip version: %d", val & 3);
 202                 return -ENOSYS;
 203         }
 204
 205         if (ov->subtype == CC_OV76BE)
 206                 ov->sops = &ov76be_ops;
 207         else if (ov->subtype == CC_OV7620)
 208                 ov->sops = &ov7x20_ops;
 209         else
 210                 ov->sops = &ov7x10_ops;
 211
 212         return 0;
 213 }
 214
 215 /* This detects the OV6620, OV6630, OV6630AE, or OV6630AF chip. */
 216 static int ov6xx0_detect(struct i2c_client *c)
 217 {
 218         struct ovcamchip *ov = i2c_get_clientdata(c);
 219         int rc;
 220         unsigned char val;
 221
 222         PDEBUG(4, "");
 223
 224         /* Detect chip (sub)type */
 225         rc = ov_read(c, GENERIC_REG_COM_I, &val);
 226         if (rc < 0) {
 227                 PERROR("Error detecting ov6xx0 type");
 228                 return -1;
 229         }
 230
 231         if ((val & 3) == 0) {
 232                 ov->subtype = CC_OV6630;
 233                 PINFO("Camera chip is an OV6630");
 234         } else if ((val & 3) == 1) {
 235                 ov->subtype = CC_OV6620;
 236                 PINFO("Camera chip is an OV6620");
 237         } else if ((val & 3) == 2) {
 238                 ov->subtype = CC_OV6630;
 239                 PINFO("Camera chip is an OV6630AE");
 240         } else if ((val & 3) == 3) {
 241                 ov->subtype = CC_OV6630;
 242                 PINFO("Camera chip is an OV6630AF");
 243         }
 244
 245         if (ov->subtype == CC_OV6620)
 246                 ov->sops = &ov6x20_ops;
 247         else
 248                 ov->sops = &ov6x30_ops;
 249
 250         return 0;
 251 }
 252
 253 static int ovcamchip_detect(struct i2c_client *c)
 254 {
 255         /* Ideally we would just try a single register write and see if it NAKs.
 256          * That isn't possible since the OV518 can't report I2C transaction
 257          * failures. So, we have to try to initialize the chip (i.e. reset it
 258          * and check the ID registers) to detect its presence. */
 259
 260         /* Test for 7xx0 */
 261         PDEBUG(3, "Testing for 0V7xx0");
 262         c->addr = OV7xx0_SID;
 263         if (init_camchip(c) < 0) {
 264                 /* Test for 6xx0 */
 265                 PDEBUG(3, "Testing for 0V6xx0");
 266                 c->addr = OV6xx0_SID;
 267                 if (init_camchip(c) < 0) {
 268                         return -ENODEV;
 269                 } else {
 270                         if (ov6xx0_detect(c) < 0) {
 271                                 PERROR("Failed to init OV6xx0");
 272                                 return -EIO;
 273                         }
 274                 }
 275         } else {
 276                 if (ov7xx0_detect(c) < 0) {
 277                         PERROR("Failed to init OV7xx0");
 278                         return -EIO;
 279                 }
 280         }
 281
 282         return 0;
 283 }
 284
 285 /* ----------------------------------------------------------------------- */
 286
 287 static int ovcamchip_attach(struct i2c_adapter *adap)
 288 {
 289         int rc = 0;
 290         struct ovcamchip *ov;
 291         struct i2c_client *c;
 292
 293         /* I2C is not a PnP bus, so we can never be certain that we're talking
 294          * to the right chip. To prevent damage to EEPROMS and such, only
 295          * attach to adapters that are known to contain OV camera chips. */
 296
 297         switch (adap->id) {
 298         case I2C_HW_SMBUS_OV511:
 299         case I2C_HW_SMBUS_OV518:
 300         case I2C_HW_SMBUS_OVFX2:
 301         case I2C_HW_SMBUS_W9968CF:
 302                 PDEBUG(1, "Adapter ID 0x%06x accepted", adap->id);
 303                 break;
 304         default:
 305                 PDEBUG(1, "Adapter ID 0x%06x rejected", adap->id);
 306                 return -ENODEV;
 307         }
 308
 309         c = kmalloc(sizeof *c, GFP_KERNEL);
 310         if (!c) {
 311                 rc = -ENOMEM;
 312                 goto no_client;
 313         }
 314         memcpy(c, &client_template, sizeof *c);
 315         c->adapter = adap;
 316         strcpy(c->name, "OV????");
 317
 318         ov = kzalloc(sizeof *ov, GFP_KERNEL);
 319         if (!ov) {
 320                 rc = -ENOMEM;
 321                 goto no_ov;
 322         }
 323         i2c_set_clientdata(c, ov);
 324
 325         rc = ovcamchip_detect(c);
 326         if (rc < 0)
 327                 goto error;
 328
 329         strcpy(c->name, chip_names[ov->subtype]);
 330
 331         PDEBUG(1, "Camera chip detection complete");
 332
 333         i2c_attach_client(c);
 334
 335         return rc;
 336 error:
 337         kfree(ov);
 338 no_ov:
 339         kfree(c);
 340 no_client:
 341         PDEBUG(1, "returning %d", rc);
 342         return rc;
 343 }
 344
 345 static int ovcamchip_detach(struct i2c_client *c)
 346 {
 347         struct ovcamchip *ov = i2c_get_clientdata(c);
 348         int rc;
 349
 350         rc = ov->sops->free(c);
 351         if (rc < 0)
 352                 return rc;
 353
 354         i2c_detach_client(c);
 355
 356         kfree(ov);
 357         kfree(c);
 358         return 0;
 359 }
 360
 361 static int ovcamchip_command(struct i2c_client *c, unsigned int cmd, void *arg)
 362 {
 363         struct ovcamchip *ov = i2c_get_clientdata(c);
 364
 365         if (!ov->initialized &&
 366             cmd != OVCAMCHIP_CMD_Q_SUBTYPE &&
 367             cmd != OVCAMCHIP_CMD_INITIALIZE) {
 368                 dev_err(&c->dev, "ERROR: Camera chip not initialized yet!\n");
 369                 return -EPERM;
 370         }
 371
 372         switch (cmd) {
 373         case OVCAMCHIP_CMD_Q_SUBTYPE:
 374         {
 375                 *(int *)arg = ov->subtype;
 376                 return 0;
 377         }
 378         case OVCAMCHIP_CMD_INITIALIZE:
 379         {
 380                 int rc;
 381
 382                 if (mono == -1)
 383                         ov->mono = *(int *)arg;
 384                 else
 385                         ov->mono = mono;
 386
 387                 if (ov->mono) {
 388                         if (ov->subtype != CC_OV7620)
 389                                 dev_warn(&c->dev, "Warning: Monochrome not "
 390                                         "implemented for this chip\n");
 391                         else
 392                                 dev_info(&c->dev, "Initializing chip as "
 393                                         "monochrome\n");
 394                 }
 395
 396                 rc = ov->sops->init(c);
 397                 if (rc < 0)
 398                         return rc;
 399
 400                 ov->initialized = 1;
 401                 return 0;
 402         }
 403         default:
 404                 return ov->sops->command(c, cmd, arg);
 405         }
 406 }
 407
 408 /* ----------------------------------------------------------------------- */
 409
 410 static struct i2c_driver driver = {
 411         .driver = {
 412                 .name =         "ovcamchip",
 413         },
 414         .id =                   I2C_DRIVERID_OVCAMCHIP,
 415         .class =                I2C_CLASS_CAM_DIGITAL,
 416         .attach_adapter =       ovcamchip_attach,
 417         .detach_client =        ovcamchip_detach,
 418         .command =              ovcamchip_command,
 419 };
 420
 421 static struct i2c_client client_template = {
 422         .name =         "(unset)",
 423         .driver =       &driver,
 424 };
 425
 426 static int __init ovcamchip_init(void)
 427 {
 428 #ifdef DEBUG
 429         ovcamchip_debug = debug;
 430 #endif
 431
 432         PINFO(DRIVER_VERSION " : " DRIVER_DESC);
 433         return i2c_add_driver(&driver);
 434 }
 435
 436 static void __exit ovcamchip_exit(void)
 437 {
 438         i2c_del_driver(&driver);
 439 }
 440
 441 module_init(ovcamchip_init);
 442 module_exit(ovcamchip_exit);